Black MIDI refers to a music genre and visual style where MIDI files are created with an absurdly high number of notes, often in the millions or billions. Originating in Japan around 2009 on sites like Nico Nico Douga, it gained massive popularity on YouTube through 'Impossible Remixes' of tracks like 'Bad Apple!!' and 'U.N. Owen Was Her?'. Visually, the piano roll becomes a solid wall of color, typically black, representing a level of complexity that would be impossible for a human to play. In meme culture, Black MIDI is frequently used to represent technological overload, 'melting' CPUs, or any situation where a person is overwhelmed by an excessive amount of information or tasks.